1. Field of the Invention
The present invention relates to an information recording/reproducing apparatus suitable for a tape streamer drive with a cassette tape having a non-volatile memory that stores information with respect to a magnetic tape.
2. Description of the Related Art
Since a tape streamer drive that records and reproduces digital data to/from a magnetic tape has a large storage capacity, it has been widely used so as to back up data stored in a storing device such as a hard disk or the like. In addition, the tape streamer drive is suitable for recording a large file that contains moving picture data.
In such a tape streamer drive, digital data is recorded/reproduced to/from a magnetic tape by a helical scan method with a rotating head using a tape cassette similar to an 8-mm type tape cassette.
In such a tape streamer drive, for example SCSI (Small Computer System Interface) is used as an input/output interface. In the recording mode, data is input from a host computer through the SCSI interface. Input data is supplied as fixed-length block data to the tape streamer drive. The input data is variable-length encoded with for example LZ code so as to compress the data. The compressed data is temporarily stored in a buffer memory. The data stored in the buffer memory is supplied as predetermined groups to a recording/reproducing system. Thereafter, the data is recorded on a magnetic tape with a rotating head. In the reproducing mode, data is reproduced from the tape with the rotating head. The data is temporarily stored in the buffer memory. The data that is output from the buffer memory is expanded to the original data. The resultant data is supplied to the host computer through the SCSI interface.
A system of which a non-volatile memory is disposed in a cassette tape loaded to a tape streamer drive that records/reproduces data with a rotating head has been proposed as Japanese Patent Application No. 8-67520 by the applicant of the present invention. In the non-volatile memory, information such as the date and place of manufacture of the tape cassette, the thickness, length, and material of the tape is recorded.
When data is stored in the memory of the tape cassette, record areas for individual information items such as the date and place of the manufacture of the tape cassette, the thickness, length, and material of the tape, management information of individual partitions, and user information are formed on the memory map so as to record data of the information items in the respective record areas. However, the storage capacity of the non-volatile memory disposed in the tape cassette is limited. In addition, when the record areas are formed for individual information items, the format of data recorded to the tape cassette and the information items cannot be flexibly changed. Thus, the storage capacity of the non-volatile memory may become insufficient or wasteful.
When one tape is divided into a plurality of partitions and data is managed for each partition, it is preferred to record management information and user information for each partition. Thus, in the case of the tape cassette with the non-volatile memory, management information and user information for each partition are stored in the non-volatile memory.
However, when management data for each partition is stored in the non-volatile memory, storage areas for management information corresponding to the number of available partitions should be provided in the non-volatile memory. Since the storage capacity of the non-volatile memory is limited, when large storage areas are assigned to the management information for the partitions, sufficient storage areas for user data and so forth cannot be obtained. In addition, when the number of partitions that have been actually formed is small, storage areas for the management information for the partitions become wasteful.
There is another type of tape cassette. This tape cassette does not have a non-volatile memory. Thus, a tape cassette with a non-volatile memory or a tape cassette without a non-volatile memory may be loaded to a tape streamer driver. Consequently, a system that allows a tape in a tape cassette without a non-volatile memory to be divided into a plurality of partitions is desired.